Submarine sound reception



May 29, 1928. I 1,671,262

. f R. L. WILLIAMS SUBMARINE SUND RECEPTION Filed April 2, 1925 52Amplifier Filter j jnnnunmnl 33 28 \27 42 2 4 24.

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A TT ORNE Y.

Patented May 29, 1928.

UNITED TES imm

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i Y. ROBERTA LONGFEIiLOW WILLIAMS, OF NEWTON, MASSACHUSETTS, ASSIGNORTOSUB- MARINE SIGNAL CORPORATION, OF BOSTON, MASSACHUSETTS, CORPORATION OFDELAWARE.

SBMARINE soUNn RECEPTION.

Application med' April 2, i925. serial No. 20,227.

TheI present invention relates to an. improvement in submarine soundreception and comprises "mainly a skin mounted aperiodic receiver in' aspecial valve within a ship and conveying the signals. received to alistener through a circuit designed for selective reception'.

One of the objects of the present invention is to present a suitableremovable mounting and removable aperiodic receiver which can be chancedwithout the necessit of the ship going` into dry dock.

Another feature of the present invention is to surround the actuateddiaphragm of the receiver by such an inertia mass that the vibrations ofthe ship will have little effect upon exciting the diaphragm or themicrophone connected therewith. n

A'further feature of the present invention is the combination of anaperiodic receiver with a filter and amplifying circuit which presentsdistinct advantages in the selective reception of submarine sound waves.

Other features of the present invention will be learned from thedescription in the specification and the drawing in. which the figureshows a part sectional view o f thereceiver and the circuit used forreception.

The receiver is, of course, installed under the water line of the vesselwhere the diaphragm will be continually adjacent to the water.

In the figure, 1 indicates the valve pro er which consists of a hollowcylinder 2, wit a gate opening 3, behind which the plunger 4 is adaptedto move into a seat 5 to close the rear of the cylinder from the outerWater. This is accomplished b turning the hand wheel 6. Both ends o thegate valve are provided with anges 7 and 8.

The front flange 7 is bolted to a composition seat 10 b means of machinescrews 9, 9, which lass t rough the latter and thread into a eavyinertia ring 11 rigidly riveted to the ships plate 12. Between the shipsplate and inertia ring is a suitable gasket 13, and likewise thecomposition scat 10 and the flange 7 are providedwith suitable gaskets14 and 15, the former between pieces ldaiig 11, and the latter betweenpieces 7 an The rear end of the cylinder 2 closedin the followingmanner. A cap 16 is firmly clamped to the flange `8by bolts 17, 17. Be-55 tween 8 and. 16 is a'suitable gasket 18.A A

stuffing vboi; 19 of'usual construction closesv the opening in the cap16, through which the stem 20 passes.

' At one end of the stein 20 is the receiving apparatus21 which will bedescribed shortly. At the opposite end of the stem 20'is a cap 22,foi-min part of a clamping means to hold the cab e 23 in position sothat no strain will be placed upon the wires withinV the stem 20.- 'lhecap 22 is threaded at 24 to against a shoulder 26 of the cap 22. Nearthe edge of the piece 25 are studs 27, 27 and nuts 28, 28 threadingthereon, the studs 27 serving to hold the piece 25 firmly against theshoulder 26 of the stein 20.' In this way the receiver 43 is held firmlyin place.

The receiver 21 consists of a rubber shell 30`having an opening in theback and a recess 31. The frontY is formed of a diaphragm 32 with abeveled edge 33 which through the pressure exerted by the piece 25 uponthe stein 20 rests firmly in the bevel o The operation of the apparatusis obvious and therefore needs little explanation. The incoming signalvibrating the diaphragm causes a change of resistance in the micro-1phone 1n the usual manner which is trans' telephone. i

In particular the 4 rubber diaphragm is practically aperiodic so that itiis-equally sensitive to all frequencies. As the result of this the lowfrequency water noises actuate the diaphragm at their own frequency.This mitted to the filter and finally heard in the receive the piece 25which normally bears'- V'(0 threading into the piece 16 and the nuts`28V icov j at all. The aim of the present system is to preserve thecharacteristic frequencies of the mcomin disturbances and filter thebands in which tese frequencies occur so that only the incoming signalis transmitted to the amplifying circuit. In this manner all opportunityof the incoming disturbing noises operating the amplifier by impactexcitation is also avoided. The present system while sensitive to veryweak noises and signals is ractically freev from disturbances of theormer, after the signals have been filtered and amplified.

In addition to this feature the ships noises are practically entirelyexcluded by the loose be coupling effected between the microphone andthe ships plate. This is effected by means of the large inertia plate11, which is rigidly riveted to the skin of the vessel, by thecomposition seat lO-and by the rubber shell 30, which only sets snuglybut not rigidly in the composition seat. The mass of the diaphragm whichis exceedingly small bein made of the rubber which is of low specificgravity is only loosely connected with a ve large inertia mass of ironof high specl c gravity, the combination o f which -may be shown bothmathematically and experimentally to be of the very loosest couling. Theresult is, therefore, that very ittle of the ships vibrations istransmitted to the diaphragm and these therefore are entirely excludedfrom the system. This is especially advantageous since the vibrations,due to the ships noises, may be of almost any frequency, depending uponthe kinds of apparatus used upon the ship. In addition the compositionseat serves another function. As it will not corrode and is only'boltedto the inertia plate, it can easily be removed when the ship is in drydock. This is an advantage over former systems used.

In describing the microphone receiver 43 above, it should have beenremarked that the present installation is adapted to be installed in thebottom of the vesseL/ In this position the button itself, that is theplane of theelectrodes, will be vertical so that the granular carbonwhich lies loose between the electrodes can come in contact with bothelectrodes and make a good electrical circuit. The installation is suchthat whatever vLarnaca position the diaphragm 32 is in, themicrophone isin a vertical position. This is accomplished by bending the stem 42 insuch a manner, thatthe button is always vertical.

and a peripheral seat, amicrophone, meansmounting said microphone onsaid diaphragm wall and means mountin said shell 1n said opening in theskin wit the outer dia hragm wall. flush with the outer skin surace,including a. large inertia member about said opening and a portionhaving a seat cooperating with said shell seat.

2. In combination a vessel having an opening in its skin, a soft rubbershell having a diaphragm wall with a plane outer portion and aperipheral seat, a microphone means mounting said microphone on saidiaphragm wall and means mounting said shell 'in said opening in theskin with the outer diaphragm wall flush with the outer skin surface,including a large inertia memr permanently secured to the skinsurrounding said opening and a seat member bolted to said inertia memberin which said shell rests.

3. In combination a vessel having an opening in its skin, a soft rubbershell having a diaphragm wall with a plane outer port-ion and aperipheral seat, a mlcrophone,l means mounting said microphone on saiddiaphragmy wall and means mounting said shell in said openin in the skinwith the outer diaphragm wal flush with the'outer skin surface includingan inertia member in which said shell sets secured to the skin and meansfor maintaining said shell firmly in said inertia member.

4.-. In combination a vessel having an opening in its skin, a softrubber 4shell havinga diaphragm wall with a plane outer'. portion and aperipheral seat, a microphone, means mounting said microphone on saiddiaphragm wall and means mounting said shell 1n said openin in the skinwith the outer diaphragm wal flush with the outer skin surface includingan inertia member surrounding said opening and a removable seat memberbolted to said inertia member in,

which said shell rests.

5. In combination a vessel having an opening in its skin, a soft rubbershell having a diaphragm exposed to the outer water ad- 'jacent to saidopening, a microphone, means mounting said microphone on said diaphragmand means mount-ing said shell in said opening in the skin with theouter diaphragm wall flush with the outer skin surface, including alarge inertia member about said opening and a portion having a seatcooperating with said shell seat.

lll

ivnaea skin with the outer diaphragm wall Hush i with the outer skinsurface, including a large inertia member about said opening and a 1uportion having a seat cooperating with said shell seat.

n testimony whereof I aix my signature.

ROBERT LONGFELLOW WILLIAMS.

